The proposed longitudinal study will experimentally test the efficacy of behavioral techniques for increasing the frequency of mammography referral among primary care physicians. Sixty practices, including at least 120 physicians and involving 18,000 women over 50 years of age, will be recruited in Springfield Massachusetts and Dayton, Ohio. These practices will be randomly assigned to one of three experimental conditions: (1) control; (2) mammography cue enhancement; and (3) mammography cue enhancement plus rewards. Interventions will be instituted for a 3-year period with periodic chart audits of a defined set of patients yielding basic data about referral. The conceptual framework is a behavioral analysis applied to physician behavior rather than to individual women. If successful, this method could prove an efficient route to reaching large numbers of women who underutilize mammography. In additional to the experimental design, data about both physician and patient characteristics will be gathered to investigate their relationship to mammography referral and completion. Physician's background, attitudes, knowledge and practices will be assessed in annual interviews; patients' age, co-morbidity, length of time with practice, and physician utilization will be obtained from chart audits. Physicians' decision rules about whom to refer can be explored with this unique set of physician and patient data. Study results will provide valuable data about the acceptance of mammography by both physicians and patients. Most important will be the test of low-cost, practical and theoretically-based behavioral management techniques to increase the rate of mammography referral to levels closer to the recommended frequencies. The applicability of these techniques to small, community-based, primary care practices will provide new insights into ways to increase early detection of breast cancer, an important public health benefit. The behavioral principles, if they hold in this study and with these behaviors, should have wide applicability in behavioral medicine with other intractable problems of patient and physician compliance.